The following abbreviations are herewith defined, at least some of which are referred to within the following description.
3GPP Third Generation Partnership Project
AP Access Point
APN Access Point Name
DL Downlink
DNS Domain Name System
eNB Evolved Node B
EPC Evolved Packet Core
ePDG Enhanced Packet Data Gateway
ETSI European Telecommunications Standards Institute
FQDN Fully Qualified Domain Name
HPLMN Home Public Land Mobile Network
IP Internet Protocol
IPsec Internet Protocol Security
LAN Local Area Network
LTE Long Term Evolution
MCC Mobile Country Code
MNC Mobile Network Code
OFDM Orthogonal Frequency Division Multiplexing
PDN Packet Data Network
PGW Packet Data Network Gateway
PLMN Public Land Mobile Network
PTR Pointer
RAN Radio Access Network
SC-FDMA Single Carrier Frequency Division Multiple Access
UDP User Datagram Protocol
UE User Entity/Equipment (Mobile Terminal)
UL Uplink
VPLMN Visited Public Land Mobile Network
WAN Wide Area Network
WiMAX Worldwide Interoperability for Microwave Access
In wireless communications networks, user equipment (“UE”) are often capable of communicating with a public land mobile network (“PLMN”) both over a cellular radio access network that utilizes licensed spectrum and a wireless local area network (“WLAN”) that utilizes unlicensed spectrum. Further, the WLAN may not be directly connected to the PLMN, rather the WLAN may communicate with the PLMN via the Internet or other data network. In certain circumstances, a UE may desire to connect to a packet core network of the PLMN to access walled-garden services offered by the PLMN operator (e.g., carrier or mobile operator). In order to connect to the packet core network via the WLAN, the UE establishes a “PDN connection” with a network element in the packet core known as an enhanced packet data gateway (“ePDG”).
Each time the UE wants to establish a PDN connection via WLAN (e.g., to access walled-garden services offered by the mobile operator), the UE must select a PLMN and then discover the IP address of an ePDG in the selected PLMN. After discovering the IP address of the ePDG, the UE establishes a secure Internet Protocol Security (“IPsec”) tunnel with the ePDG and provides an access point name (“APN”) to the ePDG. This APN is used by the ePDG to select and connect with a packet data network (“PDN”) gateway (“PGW”) which provides access to services that corresponds to the APN.
When the UE is roaming (e.g., located in a visited region) and wants to establish the PDN connection via WLAN, the UE may select an ePDG either in the HPLMN or in a VPLMN. However, in some regions there are mandatory requirements for all PLMNs in that region to support a Lawful Interception. Lawful Interception provides the ability to intercept data traffic of one or more UEs and forward the intercepted data traffic to law enforcement agencies. To comply with Lawful Interception requirements (or other mandatory requirements) for a particular region, a UE located in that region must access services via a PLMN located in that region.